Hands by the knife cut a large mouth can first use clean gauze, towels or clothing pressure bandage wound to stop bleeding, immediately to the hospital for wound debridement, tetanus antitoxin and so on. Drugs should be applied under the guidance of a doctor.
If your hand is cut by a knife, if the wound is large and deep, there may be foreign objects contaminating the wound, or there may be damage to blood vessels, nerves and other structures, it is not recommended to treat the wound on your own, and you should use clean fabrics such as gauze, towels, clothes, etc. that you can find at hand to bandage the wound under pressure to stop the bleeding as much as possible, and then go to the hospital for emergency surgery immediately.
Emergency surgery will debride the wound as appropriate, flush the wound with saline and hydrogen peroxide, disinfect with iodine povidone, clean up any foreign objects, check for any damage to important blood vessels and nerves and repair. After thorough debridement, wounds with a short time after injury and little contamination can usually be sutured directly. If the knife has rust or the wound is deep, etc., tetanus antitoxin is needed to prevent infection.